U.S. Pat. No. 3 119 933 describes a receptacle for transporting radioactive material and comprising a double wall containing screen material such as blocks of lead.
The manufacture of such a receptacle poses a problem with the insertion of the screen material between the other two walls. The insertion is even more difficult when the screen material is not in the form of relatively thick and rigid blocks, but is in the form of a thin sheet having poor mechanical qualities, as in the case for boron steel or for sheets of cadmium or cadmium alloy, for example.
Preferred embodiments of the present invention solve this problem and enable screen material to be used which is about 0.10 millimeters (mm) to 1 mm thick. The invention does not bear on a particular composition of screen material and is not limited to any such composition. Suitable screen materials include, for example, the neutron-absorbing materials described in Swiss Pat. No. 364 565 and in British Pat. No. 958 267, but it should be understood that the invention is in no way limited to these specific materials.